Determination of subasumstat in human urine using LC-MS/MS

Aim TAK-981 (Subasumstat) inhibits cancer cell growth and promotes the production of type I interferons (IFN-Is). It is crucial to establish a reliable bioanalytical assay to measure TAK-981 levels in human urine for its clinical evaluation in oncology drug development.Materials and methods TAK-981 was quantitated by LC-MS/MS assay with its stable isotope labelled internal standard TAK-981-13C4, 15N2. Samples were extracted from human urine containing 0.05% tween 20 with ACN and analyzed on an ACQUITY HSS T3 column.Results This assay was validated under regulatory guidance over a concentration range of 10 ng/mL to 2500 ng/mL and has been implemented to support clinical studies. Across all QC concentrations, the inter-run %RE ranged from −2.1% to 2.3% with %CV ranged from 2.3% to 3.0%.Conclusion To our knowledge, this is the first published LC-MS/MS assay validated for the quantitation of TAK-981 in human urine.